Geometrical characteristics and reactivities of tetracoordinated Pd complexes: Mono- and bidentate ligands and charged and uncharged ligands

Abstract

The geometrical structures, atomic charges, and relative energies of tetracoordinated Pd complexes [PdCl(3)Z (Z = Cl-, Br-, OH-, H2O, NH3, PH3) PdCl(2)Z(2) (Z = Br-, OH-, H2O, NH3, PH3), PdZ(2)X (Z = Cl- OH-, (HO)-O-2, NH3, PH3; X = oxalate, O2-CCO2-), and PdZ(2)Y (Z = Cl-, OH-, H2O, NH3, PH3; Y = succinate, CO2-CHCHCO2-)] and the ligand exchange reactions of the Pd complexes were investigated using the ab initio second order Moller-Plesset perturbation (MP2) and Density Functional Theory (DFT) methods. The geometrical characteristics of the tetracoordinated Pd(II) complexes with mono- and bidentate ligands, the effects of the atomic charges for the charged and uncharged ligands, the (d(z2)-pi) interactions between the d(z2)-orbital of Pd(IT) and the pi-orbital of bidentates, and the relative stabilities between the isomers of PdCl(2)Z(2) and PdZ(2)Y were investigated in detail. The potential energy surfaces for the ligand exchange reactions used for the conversions of ([PdCl2(NH3)(2)] + H2O) to {[PdCl(NH3)(2)(H2O)](+) + Cl-} and {[PdCl2(PH3)(2)] + H2O} to {[PdCl(PH3)(2)(H2O)](+) + Cl-]} were investigated. The geometrical structure variations, molecular orbital variations (HOMO and LUMO), and relative stabilities for the ligand exchange processes were also examined quantitatively.